What, you expected a real answer? Okay, how about this? They come from the world, from the bumping of one strange occurrence against another. Someone will say something, or do something, or the radio will sing something at you and it will MATTER in a way it wouldn’t have if the other half of this equation, you and your thoughts, weren’t there. Yes, I have taken months off to right. And yes, I am finding that leaving the house and interacting with the world now and then is a good way to find ideas.